Get something super simple that is inexpensive and gives your your coordinates. Something like the Bushnell HuntTrack or BackTrack (make sure its one of the models that displays the cords, so not the cheapest one) or if you prefer Garmin, an eTrex.
Then get some USGS quad maps of the area you want (and/or BLM maps, and/or Rocky Mountain Huntin' Maps) and a good compass in case you lose signal.
Hell, one of the guys that used to work where I work (MacVan Maps) used to GeoCache with paper maps and a compass ... said they were more accurate.
Of course if you insist on digital, we sell the Big Game CD Maps for Colorado. They have a free app for iPhone to read the maps.